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SSDs last a long time

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At 24 GB/day, or 8.8 TB/year, it would take 114 years to reach 1 PB.
Several SSDs have gone past that point, and still work fine.

Last year, I wrote about estimates for durability of SSD drives. Looking at how long it would take to exhaust the theoretical limit of the storage cells, based on different write speeds and quantities. The assertion was: It would take a very long time, and other technical failures were more likely to render the drive useless long before all cells were used up. In fact, the owner is not likely to outlive full cell exhaustion. This has now been confirmed through an experiment.

Over at Tech Report, they have done an endurance experiment lasting more than a year, with several consumer drives. For months, they have been writing data to the drives, while monitoring drive health, and verifying correctness. Some of the drives were rated for 20 GB / day for three days, which means about 22 TB. However, several of them made it past the 1000 TB, or 1 PB, mark. That’s about 50 times the advertised endurance rating. And two of the drives, a Samsung 840 Pro 256GB, and a Kingston HyperX 3K 240GB, have made to past 1.5 PB. It’s not all clear from the article exactly when they started, or how much they write per day. However, assuming a year to get to 1.5 PB, that’s 4.1 TB / day, or 47 MByte/s. The actual write speed is probably higher, but this leaves time for verification as well.

To put these numbers into perspective, I’ve extended the table from last time, and added a line for the speed of the Tech Report endurance test, as well as extra columns for multiple years total. As can be seen, the endurance test is running at 171 the write speed of what was identified as “heavy use”. Furthermore, the heavy use scenario is within what the typical consumer drives are rated for, i.e. about 20 GB/day.

MBit/s MByte/s MByte/hour GByte/day GByte/year TByte 3 years TByte 5 years
SATA3 max speed 6000 750 2700000 64800 23652000 70956 118260
Stress test 2000 250 900000 21600 7884000 23652 39420
Endurance test 376 47 171000 4109 1500000 4500 7500
Heavy use 2.2222 0.2778 1000 24 8760 26.280 43.800
Low/Medium use 0.0926 0.0116 41.67 1 365 1.095 1.825

What about the time to failure estimates; how do they compare to the empirical evidence? Last year, I noted that a 256 GB drive with cells of 10k write cycle life span (typical MLC memory), would take 256 years to reach 10% of failed cells, and about 350 years for full exhaustion, assuming 24 GB/day written. It turns out that was a bit optimistic. At 24 GB/day, or 8.76 TB/year, it would take “only” 172 years to reach 1.5 PB (where the Tech Report drives are now). If we go by 1 PB, it would take 114 years.

This is all for MLC memory. If we look at TLC, typically rated for 1000 write cycles, the endurance numbers are also a tenth. I.e. they would fail between 11 to 17 years of sustained 24 GB/day writes, again assuming a 256 GB drive.

If larger drives are used, the time to failure also increases. This is because there are more total space to level the writes across. In fact, doubling the size of the drive, will in theory double its lifespan. So an MLC 512 GB drive would last some 228 years, and a 1 TB drive 456 years. For TLC, the numbers are again a tenth, so 22 and 45 years respectively.

This is all well and good, and should at least put the final nail in the coffin regarding worries for SSD reliability. The only concern which the Tech Report experiment raises, is the way the drives fail when they do reach end of life. Of course there are plenty of relocated sector warnings in the SMART data beforehand. However, once they are past the point of no recovery, all data is lost. Several of them cannot be accessed at all. This is of course a bit different from spinning disks, which usually keep on reading some of the tracks, even if other parts are broken.

It highlights the fact that monitoring SMART data should be a standard procedure, and part of good data hygiene. Of course, a good backup strategy is required, regardless of drive type or usage pattern.

PC build: Silent yet powerful

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It’s been a long time since I’ve had the chance to put together a machine. The one I’m typing on right now has a more than five years old AMD Athlon 64 X2 5050e, and one of its HDDs report 47220 Power_On_Hours, or 5.4 years. It was fun to look at some new hardware.

This build is not for me, though. My father’s current machine is from 2005, and the AMD Sempron 2600 1.6GHz has kept up well, however would not be a good fit for the new requirements: A silent build which can handle a modern Ubuntu distribution plus Windows 7 in a VM. After good advice from Redditors on r/buildapc, I got the following components.

Main

Storage

The rest

 
 

Requirements and reasoning

At € 1055 (in June 2014), it’s not a cheap build, and I could definitely have saved a bit here and there. However, that was not my main concern – my father deserved something top-notch. I wanted something powerful enough so that it would last many years to come without upgrading, yet silent for the living room. That’s why some of the components are somewhat over-provisioned: the fanless 460W PSU, while I expect the peak draw to be less than 150W; 16 GB RAM, 256 SDD, 4 TB HDD.

For the CPU, I went for the four core Intel Core i5 4570 (LGA 1150, 3.20GHz), based on redMarllboro’s advice. It is indeed more powerful than the AMD A10-6700 I had originally planned for, and furthermore, the virtual cores would not benefit the VM much.

With the CPU fixed, I narrowed down my search for an Asus motherboard to the ASUS Maximus VII Ranger (Z97). That was based on the following criteria: more than 4 SATA ports, Intel Ethernet controller (I try to keep away from Realtek based on this issue, even if that was WiFi related), 4 DIMM slots, an onboard DVI and/or VGA port. Turns out, that really narrows it down, and about the only contender was the ASUS Sabertooth Z97 Mark 2, however that only has HDMI and Displayport embedded.

Now, one could argue that both of those MBs are overkill for what I’m building. However, most of the boards I’d be looking at would be in the €100-150 range anyway, and as price was really not a main issue here, why not go for the latest chipset? Furthermore, the “Republic of Gamers (ROG)” marketing from Asus I find somewhat misleading. The Maximus board looks aggressive in black and red, but surely it is the hardware specifications which matter. For example, the 10K Black Metallic Capacitors are welcome when cooling is an issue. Also, some of the ROG “features” in the form of software are dubious at best: How is a RAM disk a feature of the MB? On most GNU/Linux distributions, it’s there by default under /dev/shm.

For storage, an SSD is a no-brainer these days, and the only questions are: How large? And is additional storage required? 128 GB might have been just enough, but with ~50 GB for the Ubuntu host OS, ~40 GB for the VM, and ~30 GB for swap it would have been very tight. (In fact, post install, only 70 GB is left on a 256 GB disk). Doubling to 256 GB is less than double the price. I will require more storage space, so added the 4 TB spinning disk. When it comes to WD Red over Green, it’s only about €10 difference, so another no-brainer.

As the VM will be running Windows, my plan is to back it up frequently, in the hope of recovering from certain problems of that OS. Now, several people on r/buildapc thread advised against this. I suppose they are mostly right; it might be possible to lock down a Windows installation to the point where malware and adware is not a problem. The first and second issues with that are I’d have to spend a lot of time learning about it, and I would not be very interested. And why should I? A restricted install with no direct user access to system binaries and most applications delivered from a trusted cryptographically signed source has been the norm on most GNU/Linux distributions for more than a decade. It takes no effort at all, so why go with something inferior? If this machine and setup can avoid my father spending hundreds of bucks at PC Repair shops every year, it will pay itself back quickly and be a success.

 

Silent and cool

The most important requirement for this build was to make it silent. The fanless Seasonic P-460 achieves that without breaking a sweat. At normal load, which is 35 to 50 W at the power socket (220 V; in EU), I’ve measured its temperature of the PSU at 31 C. Also, the modular cable system is very nice, as it means no lose cables hanging around. In fact, there are no cables crossing the motherboard at all, as seen in this picture.

For the CPU, I had wished for passive water cooling, however most solutions on the market today are downright ugly. If the Zalman Reserator tower was still around, I would have gotten that. The compromise was therefore the over-sized Noctua NH-U14S. Again it is probably a bit of an overkill, however the benefit is that it’s not pushing the limit of the cooling, so it remains silent and cold. CPU temperatures at load is around 30 C, and at peak 45 C when the case fans kick in. The part which gets warmest is the Z97 chipset heat-sink, at around 36 C.

One of the features I appreciated most with the ASUS Maximus VII Ranger motherboard was the fan-control. Five fans can be controlled individually based on temperature. Both PWM (Pulse Width Modulation) and DC (voltage) regulation is possible, based on fan type. As seen in the pictures below, the two case fans are off when they are not needed, and kick in slowly when it gets hot. On low to normal load the CPU fan spins at 350 RPM, and can barely be heard if you put your ear right next to the case.

Finally, the only other moving part in the machine is the Western Digital 4 TB Red HDD. At a maximum rotation speed of 5400 RPM it is not dead silent, but quiet enough.

 

Building

Building this machine came with a lot of fun! The Fractal Design case was pure joy to work with. All aspects were well thought out: Easy access to left and right side (back of MB), excellent cable management, easy disk mounting slots, two large (and quiet) fans. Gone are the days of scratched and bleeding hands because of sharp edges around the case. And the fact that there are no cables criss-crossing the motherboard not only looks good, but also makes for good airflow. If I were to say anything against the case, it would have to be that it is big heavy beast.

The other components were also top notch, and caused no problems. In particular the modular Seasonic PSU and cable system is very welcome. You only have to plug in the cables you actually need, so no lose ends hanging around. The fact that the PSU comes in a pouch which competes with expensive cologne is also a nice touch.

The Noctua NH-U14S is a massive cooler. And it was another reason why I ended up with the Define R4 case; it was one of the few cases which had enough clearing for the cooling block. With a 14 cm fan it keeps the CPU nice and cool. The initial boot was without the fan, and temperatures went up to about 45 C in the BIOS. With the fan at lowest speed (about 350 RPM), it sits at around 35 C (still without having applied thermal paste; will wait till it’s shipped). The only concern I had was with fan direction. Its default orientation was to blow air from the RAM side backwards over the cooler. Currently, I’ve put it on the other side, so it sucks air over the block, and blows it right out at the rear fan. I might experiment with the difference of direction and position.

Here are a few pictures while building, followed by a couple of BIOS screen shots.

(Click for larger images.)


(Click for larger images.)

 
 

Software

As mentioned above, the goal was to have an Ubuntu installation, with Windows 7 in a VM. I chose Ubuntu 14.04 (aka “Trusty Tahr”), since it is a Long Term Support (LTS) release, and figured this would be the right balance between stability, supported hardware and packages. Other distributions I am currently using include Fedora and Debian, but for this build I figured hitting the middle-ground would be OK, thus Ubuntu. Since my father is used to Windows, I went for the simple Xfce 4 desktop, with a familiar taskbar, window icons and SHIFT+TAB application switching. As seen in the screen-shots below, it blends nicely with the seamless VirtualBox integration.

I tried and installed both the alternative Xubuntu ISO and the main Ubuntu ISO. The main difference is the default desktop, which is Xfce in the former. However, that had boot problems with Secure Boot, even after I enabled “Other OS” in the BIOS. It would install fine, but not find the boot image afterwards. It was possible to repair that by refreshing Grub, however it gave me a bad feeling at the start. The main Ubuntu ISO had now boot issues, and changing the desktop is just a matter of installing a package and selecting a different option at log-in. (The Ubuntu variations are really a bit redundant in that regard. Especially when other basic functionality, like boot, fails).

Apart from the default ISO packages, I added the following. There you can see xfce4, the VirtualBox packages, various utilities, and a few benchmarking tools. Nothing much came out of the later. Instead, see the CPU graphs below, which shows calm and moderate load while running Windows in the VM.

apt-get install autossh bonnie++ conky cpuburn dbus dos2unix elementary-icon-theme emacs evince fancontrol feh geeqie gimp git gitk gnome-icon-theme-extras gnome-icon-theme-full gnome-icon-theme-symbolic gnome-terminal gnupg gparted gthumb htop iftop imagemagick iotop k3b kdiff3 libnss-myhostname lmbench mencoder mplayer mtr nmap openssh-server parcellite policykit-1 policykit-1-gnome policykit-desktop-privileges screen smart-notifier sysbench sysstat tango-icon-theme tor tree usbutils virtualbox virtualbox-guest-additions-iso vlc wireshark xfce4 xsensors xubuntu-icon-theme

The installation of Windows in the VM is very simple. One important option to notice, is the Intel Virtualization Technology (VT-x) setting in the BIOS, as seen here. Once that is enabled, the rest is a breeze. VirtualBox comes with a brief but useful “wizard” which guides you through creating the image. I opted for a 40 GB, 2 CPU cores, 8 GB setup. After that, add the install medium (physical CD or ISO), and boot. Windows 7 will reboot about ten times, just as in the old days, but eventually will leave you with a full fledged install. Right after installation, it’s useful to add the VirtualBox Guest Additions, which amongst other things enables the seamless mode. Also, a shared mount-point is useful, and can be easily enabled through the VirtualBox settings. It automatically appears in Windows.

The CD/DVD drives are passed through, and the physical drives were mapped to similar drives in the VM. For shared directories / drives, I wanted to makes sure the they were mounted to the same Windows drive all the time, regardless of other mount points. Thus, the VirtualBox setting does not use auto-mount, and instead the directory was manually mounted as seen in the Dropbox example below.

Installing Dropbox was a matter of downloading and installing this package, and start it as an unprivileged user. Then, in order to make that available in the Windows image as well, the top Dropbox directory was shared as a drive. (Note: The Windows VM is intentionally not connected to the network). Finally, a requirement was to have that fixed on C:\Dropbox, which was achieved with a symbolic link in Windows. The following lines has to be executed in a shell run “as Administrator”:

net use x: \\vboxsvr\Dropbox
mklink /d x:\ c:\Dropbox

One of the few special applications which requires Windows, was Corel Paint Shop Pro (PSP). The usage pattern for this is typically to download something from the web, and the process it. To make this easy and seamless, I added a Firefox plug-in so every image gets an extra right-click menu item which opens the image in PSP inside the VM. Details for this is explained here.

Finally, another special Windows only application was the genealogy program Aldfaer. The requirement here was that it could be updated, over the web. To make this work, the main install is on Ubuntu, with an option to run and update from Wine. However, it runs better inside the VM, so the application folder is mapped to Windows through another shared folder in VirtualBox. I will go into detail regarding this setup in a later post.

Writing this a few months after the machine was delivered, I’ll declare it a success. Raw performance is at a very different level from what my father was used to. The machine is silent, and in fact is turned on most of the time (as opposed to the old which he never used because of fan-noise). The split Ubuntu / VM setup is slightly complicated, but seems to work out well. As expected, the Windows install has already regressed, but it is easy to go back to a previous Snapshot, instead of re-installing everything again. This machine will definitely last a long time.


(Click for larger images.)

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Storage prices

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If you need massive storage, 6 TB disks are already very competitively priced. However, the 3 TB WD Green still gives the most GB per coin. Amongst SSD, several 1 TB disks rank towards the top, but still at ten times more than magnetic. Finally, USB flash drives and SD cards are coming down in price, with a large 64 GB option at the top.

Details of updates

There has been several announcements of products you cannot buy yet lately. On the following list, all are for sale and immediate delivery.

The list has seen significant updates since last time, in product ranges, prices: Western Digital now has five colour codes for their desktop disks, three of which are included here. There is the inexpensive large but slow Green, the Red for NAS and RAID with extra warranty, and the Purple in between. Also new since February are the 5 and 6 TB disks.

At 92 Euros, the 3 TB Green is at the top of the list at 32.4 GB per Euro. It is interesting to note that the 6 TB version is already towards the top, at just a bit more than double the price; €202, or 29.6 GB/€. For external disks, the 4 TB Elements Desktop is at the top, for €135, or 29 GB/€.

Amongst the SSD disks, the largest are now at the top, with Crucial 1 TB, 512 GB, and Samsung 1 TB all around 3 GB/€. Most interesting, is the fact that the Crucial claim to be MLC while the Samsung SSD 840 EVO Basic is a TLC based disk. The Samsung MLC disk are far more expensive, starting below 2 GB/€. It a sign of a very competitive market, and further decrease in prices ahead.

Finally, lower solid state prices also benefit memory cards and USB sticks. The Sandisk Cruzer Edge 64 GB drive now gives most storage for money. A bit further down, the Sandisk Ultra 64 GB and 128 GB SD cards are good large capacity options, although with slow 30 Mb/s read and write speeds. For top write speed, at an impressive 280/250 Mb/s read/write, see the new UHS-II based 64 GB SDXC card.

The List

Media Type Product Capacity Price CHF Price Euros Euros / GB GBs / Euro
HDD Western Digital Green 3TB 3000 GB 112.00 92.56 0.03 32.41
HDD Seagate Desktop 4TB 4000 GB 159.00 131.40 0.03 30.44
HDD Western Digital Green 4TB 4000 GB 161.00 133.06 0.03 30.06
HDD Western Digital Green 6TB 6000 GB 245.00 202.48 0.03 29.63
External 3.5 Western Digital Elements Desktop 4TB, USB3 4000 GB 164.00 135.54 0.03 29.51
HDD Western Digital Purple 3TB 3000 GB 125.00 103.31 0.03 29.04
HDD Western Digital Green 2TB 2000 GB 85.00 70.25 0.04 28.47
HDD Western Digital Red 3TB 3000 GB 130.00 107.44 0.04 27.92
External 3.5 Western Digital Elements Desktop 3TB, USB3 3000 GB 130.00 107.44 0.04 27.92
HDD Western Digital Purple 4TB 4000 GB 175.00 144.63 0.04 27.66
HDD Western Digital Red 4TB 4000 GB 177.00 146.28 0.04 27.34
External 3.5 Western Digital My Book 3TB, USB3 3000 GB 135.00 111.57 0.04 26.89
HDD Western Digital Red 5TB 5000 GB 226.00 186.78 0.04 26.77
External 3.5 Western Digital My Book 4TB, USB3 4000 GB 182.00 150.41 0.04 26.59
HDD Hitachi Deskstar 7K4000, 4TB 4000 GB 184.00 152.07 0.04 26.30
HDD Western Digital Red 6TB 6000 GB 279.00 230.58 0.04 26.02
HDD Western Digital Purple 2TB 2000 GB 95.40 78.84 0.04 25.37
HDD Western Digital Red 2TB 2000 GB 104.00 85.95 0.04 23.27
External 2.5 Western Digital Elements Portable 2TB, USB3 2000 GB 109.00 90.08 0.05 22.20
HDD Western Digital Green 1TB 1000 GB 62.20 51.40 0.05 19.45
External 2.5 Western Digital My Passport Ultra 2TB, USB3 2000 GB 127.00 104.96 0.05 19.06
HDD Western Digital Purple 1TB 1000 GB 69.60 57.52 0.06 17.39
HDD Western Digital Red 1TB 1000 GB 70.50 58.26 0.06 17.16
External 2.5 Western Digital My Passport Ultra 1TB, USB3 1000 GB 75.90 62.73 0.06 15.94
External 2.5 Western Digital Elements Portable 1TB, USB3 1000 GB 77.90 64.38 0.06 15.53
DVD-R Verbatim 16x DVD-R 100 @ 4,7GB 470 GB 40.40 33.39 0.07 14.08
Blu-ray Verbatim BD-R SL 10 @ 25GB 250 GB 25.00 20.66 0.08 12.10
Blu-ray Verbatim BD-R DL 10 @ 50GB 500 GB 57.30 47.36 0.09 10.56
DVD+R DL Verbatim 8x DVD+R DL 50 @ 8,5GB 425 GB 69.10 57.11 0.13 7.44
DVD+R DL Verbatim 8x DVD+R DL 25 @ 8,5GB 213 GB 36.40 30.08 0.14 7.06
SSD Crucial MX100 SSD, MLC, 512GB 512 GB 199.00 164.46 0.32 3.11
SSD Samsung SSD 840 EVO Basic, TLC, 1TB 1000 GB 399.00 329.75 0.33 3.03
SSD Crucial M550 SSD, MLC, 1024GB 1024 GB 424.00 350.41 0.34 2.92
SSD Crucial M550 SSD, MLC, 512GB 512 GB 224.00 185.12 0.36 2.77
SSD Samsung SSD 840 EVO Basic, TLC, 500GB 500 GB 226.00 186.78 0.37 2.68
SSD Crucial M500 SSD, MLC, 960GB 960 GB 445.00 367.77 0.38 2.61
SSD Crucial M500 SSD, MLC, 480GB 480 GB 237.00 195.87 0.41 2.45
USB Flash Sandisk Cruzer Edge Flash Drive 64GB 64 GB 33.50 27.69 0.43 2.31
CD-R Verbatim CD-R 100 @ 700MB 70 GB 36.80 30.41 0.43 2.30
SSD Samsung SSD 840 EVO Basic, TLC, 750GB 750 GB 404.00 333.88 0.45 2.25
SSD Samsung SSD 840 EVO Basic, TLC, 250GB 250 GB 137.00 113.22 0.45 2.21
SSD Samsung SSD 850 Pro, MLC, 1024GB 1024 GB 635.00 524.79 0.51 1.95
SSD Samsung SSD 840 Pro Basic, MLC, 512GB 512 GB 333.00 275.21 0.54 1.86
SSD Samsung SSD 840 Pro Basic, MLC, 256GB 256 GB 167.00 138.02 0.54 1.85
USB Flash Sandisk Cruzer Edge Flash Drive 32GB 32 GB 21.00 17.36 0.54 1.84
SSD Samsung SSD 850 Pro, MLC, 256GB 256 GB 179.00 147.93 0.58 1.73
SSD Samsung SSD 840 EVO Basic, TLC, 120GB 120 GB 84.20 69.59 0.58 1.72
SSD Samsung SSD 850 Pro, MLC, 512GB 512 GB 378.00 312.40 0.61 1.64
SDXC Sandisk Ultra, SDXC, 30MB/s, 64GB 64 GB 52.00 42.98 0.67 1.49
SDXC Sandisk Ultra, SDXC, 30MB/s, 128GB 128 GB 105.00 86.78 0.68 1.48
USB Flash Sandisk Cruzer Edge Flash Drive 16GB 16 GB 13.30 10.99 0.69 1.46
SSD Samsung SSD 840 Pro Basic, MLC, 128GB 128 GB 112.00 92.56 0.72 1.38
SSD Samsung SSD 850 Pro, MLC, 128GB 128 GB 128.00 105.79 0.83 1.21
SDXC Sandisk Extreme, SDXC, 45MB/s, 64GB 64 GB 65.10 53.80 0.84 1.19
USB Flash Sandisk Extreme Pro, USB 3.0, 128GB 128 GB 135.00 111.57 0.87 1.15
SDHC Sandisk Ultra, Class 10, 30MB/s, 32GB 32 GB 35.00 28.93 0.90 1.11
USB Flash Sandisk Cruzer Edge Flash Drive 8GB 8 GB 8.95 7.40 0.92 1.08
SDHC Sandisk Ultra, Class 10, 30MB/s, 16GB 16 GB 18.80 15.54 0.97 1.03
SDXC Sandisk Extreme SDXC, 80/60MB/s, 128GB 128 GB 162.00 133.88 1.05 0.96
SDXC Sandisk Extreme SDXC, 80/60MB/s, 64GB 64 GB 89.00 73.55 1.15 0.87
SDHC Sandisk Ultra, Class 10, 30MB/s, 8GB 8 GB 12.30 10.17 1.27 0.79
SDXC Sandisk Extreme Pro SDXC, 90/95MB/s, 64GB 64 GB 117.00 96.69 1.51 0.66
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 32GB 32 GB 78.00 64.46 2.01 0.50
Compact Flash Sandisk Extreme 120MB/s, UDMA 7, 64GB 64 GB 167.00 138.02 2.16 0.46
Compact Flash Sandisk Extreme Pro 160MB/s, UDMA 7, 256GB 256 GB 709.00 585.95 2.29 0.44
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 16GB 16 GB 46.10 38.10 2.38 0.42
Compact Flash Sandisk Extreme 120MB/s, 128GB 128 GB 384.00 317.36 2.48 0.40
Compact Flash Sandisk Extreme 60MB/s, 64GB 64 GB 228.00 188.43 2.94 0.34
Compact Flash Sandisk Extreme 120MB/s, UDMA 7, 32GB 32 GB 116.00 95.87 3.00 0.33
Compact Flash SanDisk Ultra 30MB/s, 16GB 16 GB 58.50 48.35 3.02 0.33
SDXC Sandisk Extreme SDXC, 80/30MB/s, 8GB 8 GB 29.30 24.21 3.03 0.33
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 8GB 8 GB 30.30 25.04 3.13 0.32
SDXC Sandisk Extreme Pro SDXC, UHS-II, 280/250MB/s, 64GB 64 GB 247.00 204.13 3.19 0.31
Compact Flash Sandisk Extreme Pro 160MB/s, UDMA 7, 32GB 32 GB 149.00 123.14 3.85 0.26
Compact Flash Sandisk Extreme Pro 160MB/s, UDMA 7, 64GB 64 GB 333.00 275.21 4.30 0.23
Compact Flash SanDisk Extreme 60MB/s, 16GB 16 GB 84.30 69.67 4.35 0.23
Compact Flash Sandisk Extreme Pro 160MB/s, UDMA 7, 128GB 128 GB 708.00 585.12 4.57 0.22
Compact Flash SanDisk Extreme 120MB/s, UDMA 7, 16GB 16 GB 91.00 75.21 4.70 0.21
Compact Flash Sandisk Extreme Pro 100MB/s, 128GB 128 GB 776.00 641.32 5.01 0.20
Compact Flash Sandisk Extreme Pro 90MB/s, UDMA 6, 32GB 32 GB 224.00 185.12 5.79 0.17
Compact Flash Sandisk Extreme Pro 90MB/s, UDMA 6, 64GB 64 GB 452.00 373.55 5.84 0.17

Exchange rate: 1 Euro = 1.210000 CHF.

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Why 10TB drives could be bad news

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In this week’s news, Hitachi GST (HGST) announced a 10 TB HDD. It ups the earlier announcement by Seagate of a 8 TB disk. Although both companies claim the disks are “shipped”, they are nowhere near consumers yet. Both are shipping samples to a select few partners. Tech writers are ecstatic, though, and are happily re-publishing most of the official press release.

10 TB in a 3.5″ HDD is an impressive feat in itself, however the technology used to achieve it might mark the end of general purpose magnetic disks: First, this is another helium based disk from HGST, which stacks seven platters. It remains to be seen how long the helium can be contained within the disk, but is probably a lot shorter than the shelf-life of an air-based magnetic disk. Regardless of lifespan, what makes the 10 TB milestone less impressive, and even slightly worrisome, is the seven platters. That is a one-time trick. We cannot expect disks with even more platters stacked on top of each other in the future, so growth will not continue that route. It has to come from increased areal density of the bits per platter.

The brings me to the second issue with this disk: Areal density is achieved by so called Shingled Magnetic Recording (SMR). As explained by Seagate, it means that each data track is stacked slightly above the other, just like shingles on a roof. To make this work, existing data has to be re-written if something is changed in neighboring tracks. This could result in delays when writing data on an almost full disk. Furthermore, it will require special handling by the OS (in case of the “host managed” 10 TB HGST disk). Implementing that right might not be trivial. SMR based disks are in other words not drop-in replacements for all applications. Although, for scenarios which are write once (or infrequently), and read often, this is not a problem.

Combined, these two technologies will most likely take us to 20 TB and beyond. Assuming the 8 TB Seagate disk used five 1.6 TB platters, a seven platter disk would give 11.2 TB. That is of course the advantage of more platters, it amplifies any advance in areal density. Between five and seven platters, the factor is 1.4, and between four and seven it’s 1.75.

The trend of ever decreasing HDD prices will continue, even though the products might not be for everyone.

Seagate brags about 8 TB disks

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It was only a few days ago I mentioned Western Digital’s new 6 TB disks. It seems Seagate got nervous, and are now claiming to “ship” 8 TB disks. However, it is a misleading headline at best: The drives in question are not on sale anywhere, and only special “pre-production prototypes” have been given to few select partners. Furthermore, the initial batches will be aimed at enterprise customers who can afford them. As an early-adopter strategy, that makes sense, but it means you will not get your hands on one any time soon. So, the prediction from a few days ago holds: 8.4 TB is already within reach, with 7 platters * 1.2 TB, but needs special technology like helium filled drives. We will probably not have 8 TB drives before 2015.

The bit-tech article is also very light on technical detail, presumably because Seagate holds their cards close. There is no mentioned on how they have gotten to 8 TB, only that 10 TB might also be within reach soon. The later would be very interesting, since even with 7 platters it means an increase in areal density to 1.4 TB per platter. Or if we assume 5 platters, an impressive 2 TB. That will probably not reach the market before end of 2015, possibly 2016.

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6 TB disks, 1.2 TB platters finally here

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Earlier this week, Anandtech could report that Wester Digital has finally taken the next incremental step in spinning HDD size. The WD Red series will now come in sizes of 5 and 6 TB, as will the Green series. 6 TB is accomplished using 5 platters, which is a new trend for Western Digital. As mentioned earlier, the five-platter technology was acquired from Hitachi, and we now start seeing them in NAS type WD drives. With five platters, it means each has 1.2 TB, which is shy of the 1.25 TB expected this year. It is important, since it means the 5 TB version also contains five platters, of 1 TB each, rather than 4 * 1.25 TB.

As the AnandTech article points out, WD is still using Perpendicular Magnetic Recording (PMR) technology, as in previous drives. It means that the 1.2 TB areal density should be easily compatible with the HGST seven platters helium drives. That should make 7 * 1.2 = 8.4 TB drives immediately possible. However, as marketing seems to be focused on whole integer increments only, expect 7 and 8 TB drives in this combination. That would be in line with the predictions seen here last year.

As for price, the WD Green is not yet announced. For the Red series, 5 TB will be $250, and 6 TB $300, which puts both in at 5 cents per GB. That is 39% more expensive than the cheapest Seagate 3 TB disk in the storage graphs. However, the newest and biggest drives always start at a premium for the early adopters. These new drives will probably mean that the previous step, 4 TB, will rise to the top as the best GB per buck.

Historical Cost of Computer Memory and Storage

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I’ve finally gotten around to update the graph and data at hblok.net/storage. Since it has been a while since last time, I thought I would be left with a gap in the data. However, John C. McCallum who collected the original data got my back. I’ve incorporated his newer data points, as well as automated my own collection. Hopefully, it will not go quit so long between updates in the future.
 
 

RAM prices up

 
Due to a fire at the Hynix Fab plants in 2012, RAM prices are significantly up, and still at 2012 prices. Joel Hruska at extremetech.com has an interesting analysis into its effects. In the chart below, he notes that prices doubled after the fire. The latest data I’ve collected show that it’s going in the right direction again. However, as Hruska also points out, the market for desktops is in decline, and laptops, tablets and phones will not need the same memory types.


 
 

HDD / Magnet disk prices go sideways

 
In 2011 flooding in Thailand caused major damage to HDD factories of Western Digital, Samsung, and Toshiba. Prices have almost recovered from that by now, however it means a set-back in the HDD trend by almost three years.

In another article by Joel Hruska, he includes the graph below from Backblaze who plotted real and estimated prices on different HDD types. Although he takes issue with Backblaze’s extrapolation, it did get the significant lag of the trend right.

Furthermore, larger drives have yet to materialize. The 6 TB HGST (owned by Western Digital) Ultrastar He6 has been out for a while. Paul Alcorn at tweaktown.com discussed the details in a review a few months back. The trick is to put a whopping seven platters into the drive (as opposed to the normal three to five). However, to make that work, the drive has to be sealed and filled helium; thus its name. The new technology comes at a higher prices: It retails at Amazon for $476.99, or $0.0794/GB. That’s more than double the Seagate 3TB at $109.99 or $0.0367/GB.

So although the helium technology has a long way to go, it could be the next step for higher capacity drives. At 6 TB over 7 platters, each hold only 857 GB. That is a bit off from the 1 TB platters which have been available for a long time now, and we were “promised” 1.25 TB platters by the end of this year. If the later are compatible with the “7Stac” technology, it could mean 1.25 * 7 = 8.75 TB drives in the future. If pricing also improves, it could be that the magnetic hard disk trend is back onto its 40 year track.

 
 

SSD and flash prices down

 
Flash memory and Solid State Drives have no accidents hampering their growth and price decline. The trend is linear (i.e. on the logarithmic scale) over the last ten years. Larger drives are also gradually becoming available, with SanDisk recently announcing their enterprise 4 TB Optimus MAX SAS, and predicting 8 TB SSDs by next year. In that Computer World article, they’ve included a Gartner graph, seen below, which predicts SSD price parity with HDD by 2017. It’s important to note that they compare enterprise drives here, which live in a completely different world than the cheapest and biggest consumer drives.

For the chart I’m tracking, it is mostly the USB sticks that make it to the top, with the best price / capacity ratio. At this point, it seems that is not because the USB sticks are getting larger, but rather that the smallest ones are getting cheaper. SanDisk is now “giving away” 8 GB drives for less than $3 (although that does not give you free shipping at NewEgg).

 
 

Updated overall graph

Finally, the updated graph. The permanent link is hblok.net/storage
 

(Click for larger image)

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Trends: Old social networks are past their peak – What’s next?

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The doom and gloom of Facebook has become a common story. For example based on of a redesign of the page, or the fact that 14-year-olds wouldn’t want to be seen on the same social network as their parents. It’s usually speculation, however according to the last link, it is now also admitted in Facebook’s own earnings announcement. Furthermore, the search trends on Google also confirm the shift in interest.

Before jumping into these graphs, it is worth pointing out some caveats, even though they should be obvious: First, historical trends are no guarantee of future events. Secondly, the numbers are not absolutes, but capped fractions of Google’s keyword distribution. Thirdly, most of the searches will be “navigational”, that is typing “facebook” in the URL bar will invoke a Google search, and then immediately take the user to the top result. Therefore, part of the shift in the search trends might be that more people are using native mobile apps where such “navigation search” is not required. Fourthly, these trends are for Google searches, which of course exclude users of search engines like Bing, Yandex, or almost any Chinese user. Finally, statistics lie and cannot always be trusted. You have been warned.

Never the less, there are noticeable changes in the social and communication network landscape. Facebook, Twitter and Flickr seem to have reached a peak and might plateau or decline, while new-comers like Instagram, Reddit, WhatsApp, Snapchat all see steady growth. And then there are the solid stayers who full-fill basic communication needs and services: Gmail, Hotmail, Youtube, etc. They stay, but without much change in their search trends.
 

Past their peak

 
The following graphs show the search trends for the terms Facebook, Twitter, and finally Flicker and Picasa compared. (The reason more of the graphs are not compared is that the numbers are often on very different scales. E.g. compare Facebook to Google+, and the later hardly registers as a blip on a flat line a bit over zero). All the sites below show clear decline past their peak point. That peak was some time in 2013 for Facebook and Twitter, while Flickr and Picasa had a peak around 2010 and bumpy decrease in interest ever since.

What’s noteworthy about the Facebook graphs is first the significant and sudden increase around the beginning of 2013. It is unclear what caused this, however looking at the country specific graphs it is more present in Brazil than the others. From the Orkut graph below, it drops right down since mid-2012. That was about the same time that network was all but turned off by Google. It could explain some of the increase in searches for Facebook.

Secondly, what’s interesting about the country specific Facebook graphs are the relatively flat lines for UK and US, while Brazil and India come later to the party, but show rapid increase. Again, this is probably due to the Orkut effect, since that is where that network was most popular. Beyond that, we should be careful reading too much into that chart, since numbers are not normalized, nor adjusted for population, etc. Still, all trends are clearly down for Facebook in every country.

For the other networks, it is interesting that Twitter seems to follow the same trend as Facebook, albeit at a much lower scale. (Compare the two in the same chart, and they are some two multitudes apart). Although there is not much linking Facebook and Twitter, they do perhaps belong to the same era of sorts. Gaining widespread popularity around the same time in 2009, the same people might have been users of both, and now start to lose interest in both. It will be interesting to see if those comparative trends continue.

Finally, Flickr and Picasa are shown together, both declining over the last four to five years. What’s perhaps most interesting here is that they follow each other so closely. So how do people share photos if not on these services? Look no further than the graphs and section below: Instagram and Pinterest are the new Flickr and Picasa.


 

What does decline look like?

 

So how does a social network or popular website decline? The following graphs show some large networks through their rise, peak and fall. The common theme in all of them: There is no coming back. Once a trend has faded, it is gone, and the users have moved on. So even if they are not on the list of defunct networks yet, expect no return to greatness. At least in fashion and culture, there is the concept of retro. With ICQ and MySpace, probably not so much. Having said that, the Wikipedia article on ICQ claims there are still 100 million users, but also points out that those are mostly in Russia and Eastern Europe. Google Search might not have such a strong foothold there as in the West, thus that popularity is not reflected in this graph.

The other sites share a similar story: Although MSN is still in use by many, Facebook, Whatsapp, and plenty of built-in chat applications in everything from Gmail to World of Warcraft have taken its place in instant messaging. Orkut has more or less been merged with Google+, and I’m actually not sure if you are able to log in to what once was the Orkut specific site.

Digg lingers on, with a few attempts to stay relevant, but most users have moved on to other forums. Mostly to Reddit, it seems, from the discussion there. See the Reddit chart below.

Finally, nobody would want to be seen on MySpace anymore. Once the hip place for up-and-coming artists, it is now a has-been. Even so, it still claims some 30 million users, and in 2011 was bought by Specific Media Group and Justin Timberlake. It is not clear what they wanted to do with the site, but it might have been cheaper to launch a new service under a new domain. $30 M is after all a bit expensive for the old domain, especially since fewer and fewer searches link there.


 

Who wins? Who stays?

 
Now for the winners of the Internet based game of musical chairs. Some clear “hockey stick charts” can be seen: WhatsApp, SnapChat, Instagram, and Pinterest have all seen drastic increase in user interest over the last two to three years, all with no or little sign of decline. Furthermore, Reddit see continued growth. Then there are a group of services which continue to linger on, with no spectacular increase in interest, but overall very solid user numbers. These include the common email services Gmail, Hotmail and Yahoo, as well as Youtube for video sharing.

In the first graph below, it is interesting to note the significant down-tick in WhatsApp’s graph. According to the news annotations on Google Trends, this was exactly at the point where Facebook’s purchase of the company was announced. At the same time, we can see a stark increase in interest for the competing service SnapChat. For $19 billion dollars, Facebook might have bought the most expensive domain name of all time in an attempt to stay on an upwards trend. It will be interesting to watch how these trends develop over the coming year.

Next is the photo sharing site Instagram compared to Reddit, however maybe it would have been more natural to compare it to Pinterest. Either way, Instagram is clearly seeing strong and increasing interest. However, what will happen when it loses its “hipster” early adopter appeal? Many of its initial users seem to have been of the type which live to shun the mainstream. Other photo upload services like Tumblr, and Imgur are also popular. The former is flatting out a bit, while the later is mostly tied to Reddit, and see steady growth.

As for the discussion forum and online community site Reddit, they continue to see consistent growth. They are catering to pretty much anybody who care to make a group on any particular topic, and have shown very little sign of censuring content. It could turn out to be the Usenet or Yahoo groups of this decade.

The next chart compares Google+ to Pinterest, more as a reference point than those two being related in any way. What’s interesting to see though, is the extreme marketing power which comes with any new product Google launches. At its announcement in June 2011 everybody wanted to know what it was about, however that interest clearly did not keep up. In that regard it’s compelling to compare it to Pinterest, which saw a similar high spike, but managed to keep that momentum going, although with little increased growth.

The penultimate graph shows Youtube, with slow and bumpy growth. The site can handle videos which attract billions of views, so it is clear that there are few or no competitors out there for video sharing at such an enormous scale. However, as a social network and communication tool it is perhaps less successful. Once infamous for the most banal useless and outright hostile user comments on the Internet, they now face user revolt over Google+ integration. If all Youtube provide is infrastructure for large files, which happen to be video, they might be overtaken. If on the other hand, they manage to take the next step into the living room, and replace the TV, they could see growth in years to come.

The final graph compares the three large email providers Gmail, Hotmail, and Yahoo. Although there are some shifts in interest for all of them, it is nowhere the ups and downs seen in the other charts above. These providers will stay around for a long time, since email will continue to be relevant even if young Facebook users might deny it. Email will continue to be used for communication with businesses, registration to almost everything on the Internet, as well as conventional letter communication. Furthermore, both Hotmail and Gmail are gateways into other products from Microsoft and Google. For example, all Windows and Android users are now strongly compelled to sign up for an account with their respective companies. Gmail also contains an alternative to Skype (which is missing from the chart; although their trend is also rather flat) voice and video communication in the form of Hangouts. In other words, these services are not fads, but rather form the backbone of basic Internet based communication. The reason the don’t see further growth, is probably because they are coming close to saturating their current markets.

 

Federated services

 
What does the future of social networking and communication look like. It would be foolish to try to predict who will come out on top. There are too many factors and too many unknowns. However, it seems safe to bet on a few basic trends, founded on core ways of communicating. These would fall into the following groups:

  • Asynchronous letter based communication; e.g. mail, email.
  • Live voice and video communication; e.g. phone and video conferencing.
  • Informal messaging, both instant and asynchronous; e.g. chat, SMS.
  • Networking, self-promotion; e.g. social networks.

My prediction is that all these types of communication will stay and have strong presence in decades to come. It is maybe a boring prediction, since at its core it says that everything will stay the same. However, looking at very broad lines that has been the case for centuries. We tend to get blinded by new shiny technology and fashion, and forget that rounded corner on an iPhone does not change the basic form of communication which is voice over a telephone network.

Another example is letter or asynchronous one-to-one targeted message based communication. That has existed for millennia, with modern postal systems perhaps being one of few the significant changes before email arrived. We tend to take the fact that a letter or postcard can be sent from anywhere to anywhere in the world for granted, just as we take the Internet based electronic mail infrastructure for granted. What is important to highlight with both systems is that they are federated. That is, a message can be sent between different, possibly heterogeneous, countries or email systems / servers, without the users of these systems having to worry about infrastructure implementation. For the postal system, that is thanks to the Universal Postal Union, and for email is because of common APIs, where the SMTP (Simple Mail Transfer Protocol) is at the core. It is important, because this is a property which is missing from many modern web based communication tools.

Old style telephone networks also have this property: You can call from any wired or wireless phone in the world to any other, crossing multiple networks involving many different technologies. That has been the case for more than hundred years. “[S]ince the introduction of the public telephone system in the late 19th century, [it has stayed] mostly unchanged despite the introduction of Touch-Tone dialing, electronic telephone exchanges and fiber-optic communication into the public switched telephone network (PSTN).” (Wikipedia) The notable addition in recent times is video based calling, however that does not change the form and motivation for this kind of communication much. It is still mostly used to bring people closer together, to hear eachother’s voice, or see eachother’s face. It is instant synchronous and intimate. Which of course is why it is preferred by telemarketers; it is often harder to hang up on a call than to throw away flyers received in the mail box.

Compared to mail and phone, SMS and chat are all relatively new communication forms. Perhaps that is why it is not always clear how to relate to them. For example, is SMS and chat asynchronous or synchronous? From a technical point of view, they are both asynchronous: Both parties can send messages without waiting for the other, and message passing is starting and stopping independently. However, using it that way is typically not acceptable. It would be considered as rude to flood the other party with messages, just as it would be rude to interrupt while talking, or not let the other speak. However, how quickly are you expected to reply to a chat message or SMS? Is it instant, as the IM name suggests, or is it acceptable to linger? For how long? There are no set social protocols or rules here, and different communities will make them up as they go along.

Despite those uncertainties though, two things are clear: Instant messaging in the form of chat, SMS, WhatsApp or other implementations will stay as a separate communication form for the foreseeable future. Secondly, most of these services are currently not federated: That is, you cannot send a MSN message to a WhatsApp or Yahoo Chat user. That seems ripe for change. In fact, there is already a protocol for federated instant messaging: XMPP (Extensible Messaging and Presence Protocol) (aka. Jabber). It still has some way to go before it becomes the preferred way of exchanging chat messages, and there might in fact be other protocols which supersedes it. Regardless, the isolated short-message services we’ve seen over the last twenty years will be forced to standardize. Only then can they become stable back-bone services like the email providers seen in the chart above. The alternative is fads which come and go, which is what we can see in the graphs for the services of today.

The same is bound to happen for other web based communication as well, including video communication, VoIP (voice over IP), and social networking. Currently, you cannot call a Skype user from a Google Hangouts account. For VoIP, SIP (Session Initiation Protocol) is an important protocol, but there are many more often conflicting standards involved. For video, it gets even more complicated, with a long list of video formats, but few standards, and even fewer open standards which would be a necessity for a truly open federated system. (Email would not have gotten where it is today if the SMTP, POP and IMAP RFCs had been patented and closed).

Finally, something similar might happen for social networking, although that is the furthest out, and might not happen at all if the large “social networks” turn out to be mere promotion platforms and substitutes for self-hosted web sites. The feature that would make most sense to standardize on for social networks is the contacts or friends graph. That way, you could create a graph between users of different services like Facebook and Google+. Your contacts on your phone might also appear in your chat, and your social network, and all platforms would understand the links to other users across networks. Of course, that is exactly what many users might not want, as I touched on at the very beginning of this article. You could have something like the Google+ circles concept, where groups of friends and family can be segregated into different audiences. Is this something the causal user is ready to manage? Or will he just create different account for different purposes? Regardless, there would still be benefit in a federated social graph, as it would not matter where an account lived, and one would not have to chase the latest trend, just as email users stay relatively stable today.

On the other hand, if sites like Facebook and Google+ are mere content hosts similar to blogs and web sites, the contact graph might not be so important. It becomes a publishing platform for people who cannot or will not set up their own host and website. If that is the case, what is more important for the user, is that the content can be exported from one site and imported into another. Less he becomes a tenant or even serf locked to his host. Some services have been good at offering those features. However, it will leave them vulnerable to shifting trends and users moving on. Finally, for users who just use Facebook for the games that are hosted there, no message interchange or federation would be required. It is just a content provider and host which can be swapped out at any time. When Facebook dies, will the next FarmVille simply be hosted on Amazon EC2?

 

Conclusion

 

The search popularity of the major web sites and services above show the repeating cycles of culture and trends. Some sites and networks become popular, at the expense of others which fade away. Meanwhile, basic communication forms like letter writing and voice continue to be used in exactly the same way they have for centuries. The underlying technology might change, and modern objects will always seem more shiny and fashionable, but the mode of communication does not change.

The outstanding question is what will happen to the new forms of communication, like instant messaging and networked self-promotion. It seems unlikely they will continue to be hosted on separate technology islands, without any interchange. Instant Messaging might see a standard and federated service providers, like email, in the form of XMPP or other standard protocols.

For social networks and self promotion, there are some functionality to standardize on, like the social graph and contact list. However, as a self-promotion and publication tool, perhaps the standard is already there in the form of the HTML based web itself. If the user information, contacts and relations could be a separate federated service, independent of the web site, Facebook or similar platforms would no longer have such a stronghold. Some attempts at this are already in place: Diaspora, identi.ca, and GNU Social are interesting alternatives. Although, all have a long way to go before they reach mainstream.

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Storage prices

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The new year has not seen major changes to the prices of spinning disks. However, on the SSD side, there are some interesting news, with Samsung really gearing up. Their 840 EVO and Pro series are now amongst the most affordable and reliable disks on the market.

The EVO series uses TLC memory, which stacks more bits per cell. This increases speed, but decreases reliability. The rule of thumb is 1000 writes for TLC memory, while MLC might be 10 times higher at 10k writes. It means that TLC disks will typically be for low to medium consumer use, while MLC is for higher pro use (as the series name also suggests). This is also reflected in Samsung’s warranty: Three years on the TLC disks, which is good, and an impressive five years on the MLC Pro disks. By comparison, Western Digital’s Red series has three years warranty, while the Green series has only two years.

Also notable is the fact that for the first time price per byte is lower for an SSD disk than a stack of 100 CD-Rs. That is of course because the 100 CD stack has stayed at about 30 Euros for the last six or more years. Never the less, it underlines the fact that 2014 will be the year when decent sized SSDs reach reasonable prices. Upgrading an older laptop with a 500 GB or 750 GB SSD is soon at a point where it makes sense, and will give good return on investment.

Media Type Product Capacity Price CHF Price Euros Euros / GB GBs / Euro
Harddisk Seagate Barracuda 4TB 4000 GB 164.00 134.43 0.03 29.76
Harddisk Western Digital Caviar Green 3TB 3000 GB 125.00 102.46 0.03 29.28
Harddisk Western Digital Caviar Green 4TB 4000 GB 169.00 138.52 0.03 28.88
Harddisk Western Digital Caviar Green 2TB 2000 GB 91.00 74.59 0.04 26.81
External 3.5 Western Digital My Book Essential Edition 4TB, USB3 4000 GB 183.00 150.00 0.04 26.67
Harddisk Western Digital Red 4TB 4000 GB 185.00 151.64 0.04 26.38
Harddisk Western Digital Red 3TB 3000 GB 139.00 113.93 0.04 26.33
External 3.5 Western Digital My Book Essential Edition 3TB, USB3 3000 GB 143.00 117.21 0.04 25.59
Harddisk Hitachi Deskstar 7K4000, 4TB 4000 GB 191.00 156.56 0.04 25.55
External 2.5 Western Digital Elements Portable 2TB, USB3 2000 GB 119.00 97.54 0.05 20.50
Harddisk Western Digital Caviar Black 4TB 4000 GB 260.00 213.11 0.05 18.77
Harddisk Western Digital Caviar Green 1TB 1000 GB 67.00 54.92 0.05 18.21
External 2.5 Western Digital My Passport 2TB, USB3 2000 GB 135.00 110.66 0.06 18.07
External 2.5 Western Digital Elements Portable 1TB, USB3 1000 GB 82.00 67.21 0.07 14.88
Blu-ray Verbatim BD-R SL 25 @ 50GB 1250 GB 238.00 195.08 0.16 6.41
DVD+R DL Verbatim 8x DVD+R DL 25 @ 8,5GB 213 GB 42.00 34.43 0.16 6.17
DVD-R Verbatim 16x DVD-R 100 @ 4,7GB 470 GB 96.00 78.69 0.17 5.97
DVD+R DL Verbatim 8x DVD+R DL 10 @ 8,5GB 85 GB 36.00 29.51 0.35 2.88
SSD Samsung SSD 840 EVO Basic, TLC, 750GB 750 GB 339.00 277.87 0.37 2.70
CD-R Verbatim CD-R 100 @ 700MB 70 GB 35.00 28.69 0.41 2.44
SSD Samsung SSD 840 EVO Basic, TLC, 1TB 1000 GB 555.00 454.92 0.45 2.20
SSD Crucial M500 SSD, MLC, 120GB 120 GB 78.00 63.93 0.53 1.88
SSD Samsung SSD 840 EVO Basic, TLC, 500GB 500 GB 329.00 269.67 0.54 1.85
SSD Sandisk Ultra Plus, MLC, 256GB 256 GB 172.00 140.98 0.55 1.82
SSD Samsung SSD 840 EVO Basic, TLC, 250GB 250 GB 171.00 140.16 0.56 1.78
USB Flash Sandisk Cruzer Flash Drive 32GB 32 GB 23.00 18.85 0.59 1.70
SSD Kingston HyperX 3K, MLC, 240GB 240 GB 186.00 152.46 0.64 1.57
SSD Samsung SSD 840 EVO Basic, TLC, 120GB 120 GB 99.00 81.15 0.68 1.48
SSD Samsung SSD 840 Pro Basic, MLC, 512GB 512 GB 439.00 359.84 0.70 1.42
SSD Samsung SSD 840 Pro Basic, MLC, 256GB 256 GB 229.00 187.70 0.73 1.36
SSD Kingston SSDNow KC300, MLC, 120GB 120 GB 111.00 90.98 0.76 1.32
SSD Corsair Force GT, MLC, 240GB 240 GB 222.00 181.97 0.76 1.32
SSD Sandisk Extreme, MLC, 480GB 480 GB 457.00 374.59 0.78 1.28
SSD Corsair Neutron, MLC, 128GB 128 GB 129.00 105.74 0.83 1.21
SDXC Sandisk Ultra SDXC, Class 10, 15/30MB/s, 64GB 64 GB 67.00 54.92 0.86 1.17
SSD Corsair Force GT, MLC, 120GB 120 GB 126.00 103.28 0.86 1.16
SSD Samsung SSD 840 Pro Basic, MLC, 128GB 128 GB 139.00 113.93 0.89 1.12
USB Flash Sandisk Cruzer Flash Drive 16GB 16 GB 18.00 14.75 0.92 1.08
SDHC Sandisk Ultra, Class 10, 15/30MB/s, 32GB 32 GB 37.00 30.33 0.95 1.06
USB Flash Sandisk Cruzer Extreme 64GB 64 GB 97.00 79.51 1.24 0.80
SDHC Sandisk Ultra, Class 10, 30MB/s, 16GB 16 GB 27.00 22.13 1.38 0.72
SDXC Sandisk Extreme SDXC, UHS-I, 80/60MB/s, 64GB 64 GB 119.00 97.54 1.52 0.66
SDHC Sandisk Ultra, Class 10, 30MB/s, 8GB 8 GB 16.00 13.11 1.64 0.61
SDHC Sandisk Extreme, Class 10, 30MB/s, 16GB 16 GB 35.00 28.69 1.79 0.56
USB Flash Sandisk Cruzer Flash Drive 8GB 8 GB 18.00 14.75 1.84 0.54
SDXC Sandisk Extreme Pro SDXC, UHS-I, 95/45MB/s, 64GB 64 GB 148.00 121.31 1.90 0.53
SDHC Sandisk Extreme Pro, Class 10, 90/95MB/s, 32GB 32 GB 78.00 63.93 2.00 0.50
Compact Flash SanDisk Ultra 200x, 16GB 16 GB 49.00 40.16 2.51 0.40
Compact Flash Sandisk Extreme 800x, 120MB/s, 128GB 128 GB 426.00 349.18 2.73 0.37
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 8GB 8 GB 27.00 22.13 2.77 0.36
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 16GB 16 GB 55.00 45.08 2.82 0.35
Compact Flash Sandisk Extreme 800x, 120MB/s, 64GB 64 GB 230.00 188.52 2.95 0.34
Compact Flash SanDisk Extreme 400x, 60MB/s, 32GB 32 GB 123.00 100.82 3.15 0.32
Compact Flash Sandisk Extreme Pro 160MB/s, 256GB 256 GB 1306.00 1070.49 4.18 0.24
Compact Flash Sandisk Extreme Pro 600x, 90MB/s, 16GB 16 GB 126.00 103.28 6.45 0.15

Exchange rate: 1 Euro = 1.220000 CHF.

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VGA adapter for the Raspberry Pi

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Just tested a HDMI to VGA adapter for the RPi with my old CRT 1024×768 monitor. It works great! This was the HD2V04 HDMI to VGA + 3.5mm Audio Jack Converter Adapter Box from DealExtreme, at $21.70. The VGA port was a bit tight, so I had to make sure it was properly connected. Also, the monitor did not display anything before a cold restart of the Pi. It comes only with a USB power cable, to it means a wall wart or powered USB hub is required. (It should go without saying that you don’t want to power it off the Pi itself).

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WiFi adapters for the Raspberry Pi

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A few months back I bought a couple of cheap USB WiFi adapters from DealExtreme. Today I finally got around to try them on the Raspberry Pi. Of the three adapters, two works both on a Fedora 17 64 bits based desktop as well as on the RPi. Notice that they both seem to contain the same chip, and indeed reports the same vendor and product ID. The last, the EDUP device, does detect available WiFi networks, but usually does not establish a connection (the very last time I tried, it suddenly did). I suspect it might be a USB power issue, since it also “crashed” the USB hub on the desktop, causing the keyboard and mouse to temporarily disconnect. Here are some notes which might be related. Of the three, the one with antenna is fastest at establishing the connection, but the other small adapter also gives good transfer speed; around 3.6 Mb/s seen today, but I expect it can go faster.

For other devices supported by the RPi, see the the Embedded Linux WiFi page, and also Element 14′s WiFi testing page.

Product Description USB kernel info NetworkManger info Fedora 17 x86_64 Raspbian “wheezy” Comment
USB 2.0 2.4GHz 802.11b/g/n 150Mbps WiFi/WLAN Wireless Network Adapter USB 2.0 2.4GHz 802.11b/g/n 150Mbps WiFi/WLAN Wireless Network Adapter idVendor=148f, idProduct=5370
Product: 802.11 n WLAN
Manufacturer: Ralink
SerialNumber: 1.0
driver: ‘rt2800usb’ OK OK Works “Plug & Play”.
Connection is established quickly.
Mini USB 2.4GHz 150Mbps 802.11b/g/n WiFi Wireless Network Card Adapter - Black Mini USB 2.4GHz 150Mbps 802.11b/g/n WiFi Wireless Network Card Adapter – Black idVendor=148f, idProduct=5370
Product: 802.11 n WLAN
Manufacturer: Ralink
SerialNumber: 1.0
driver: ‘rt2800usb’ OK OK Works “Plug & Play”.
Somewhat slow at establishing the network connection.
Ultra-Mini Nano USB 2.0 802.11n 150Mbps Wifi/WLAN Wireless Network Adapter Ultra-Mini Nano USB 2.0 802.11n 150Mbps Wifi/WLAN Wireless Network Adapter idVendor=0bda, idProduct=8176
Manufacturer: Retek
driver: ‘rtl8192cu’ Failed.
Hangs USB host.
Failed.
Works 1 out of 10 times. Crashes the RPi.
Device detected, and sees available WiFi networks, hover does usually not get a connection.
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Storage prices

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4 TB is finally at the top now, giving most storage for money. Both the Western Digital and Seagate drives are priced at 144 Euros, making them the new ideal disk for a large storage or backup systems. Furthermore, WD has put out a 4 TB in their My Book external series, which again gives more bytes per coin than its 3 TB little brother.

On the Sandisk Compact Flash end of the list there are also some interesting additions. They have added new Extreme Pro editions, at 120 MB/s and at a really extreme 160 MB/s read/write speed. On their own marketing page, they claim these cards are suited for shooting “4K” (e.g. 3840 × 2160 or 4096 × 2160). However, these cards are expensive, at 630 Euros for 128 GB, and 1200 Euros for 256 GB; not for the hobbyist in other words.

Media Type Product Capacity Price CHF Price Euros Euros / GB GBs / Euro
Harddisk Western Digital Caviar Green 4TB 4000 GB 179.00 144.35 0.04 27.71
Harddisk Seagate Barracuda 4TB 4000 GB 179.00 144.35 0.04 27.71
Harddisk Western Digital Caviar Green 3TB 3000 GB 135.00 108.87 0.04 27.56
External 3.5 Western Digital My Book Essential Edition 4TB, USB3 4000 GB 184.00 148.39 0.04 26.96
External 3.5 Western Digital My Book Essential Edition 3TB, USB3 3000 GB 143.00 115.32 0.04 26.01
Harddisk Western Digital Red 3TB 3000 GB 145.00 116.94 0.04 25.66
Harddisk Western Digital Red 4TB 4000 GB 199.00 160.48 0.04 24.92
Harddisk Hitachi Deskstar 7K4000, 4TB 4000 GB 199.00 160.48 0.04 24.92
Harddisk Western Digital Caviar Green 2TB 2000 GB 107.00 86.29 0.04 23.18
Harddisk Western Digital Caviar Black 4TB 4000 GB 264.00 212.90 0.05 18.79
External 2.5 Western Digital Elements Portable 2TB, USB3 2000 GB 137.00 110.48 0.06 18.10
External 2.5 Western Digital My Passport 2TB, USB3 2000 GB 139.00 112.10 0.06 17.84
Harddisk Western Digital Caviar Green 1TB 1000 GB 70.00 56.45 0.06 17.71
External 2.5 Western Digital Elements Portable 1TB, USB3 1000 GB 83.00 66.94 0.07 14.94
External 2.5 Western Digital My Passport 1TB, USB3 1000 GB 84.00 67.74 0.07 14.76
External 3.5 Western Digital My Book Essential Edition 1TB, USB3 1000 GB 105.00 84.68 0.08 11.81
Blu-ray Verbatim BD-R SL 25 @ 50GB 1250 GB 238.00 191.94 0.15 6.51
DVD+R DL Verbatim 8x DVD+R DL 25 @ 8,5GB 213 GB 42.00 33.87 0.16 6.27
DVD-R Verbatim 16x DVD-R 100 @ 4,7GB 470 GB 96.00 77.42 0.16 6.07
DVD+R DL Verbatim 8x DVD+R DL 10 @ 8,5GB 85 GB 36.00 29.03 0.34 2.93
CD-R Verbatim CD-R 100 @ 700MB 70 GB 35.00 28.23 0.40 2.48
SSD Samsung SSD 840 Basic, TLC, 500GB 500 GB 333.00 268.55 0.54 1.86
SSD Sandisk Extreme 480GB 480 GB 339.00 273.39 0.57 1.76
SSD Corsair Neutron 256GB 256 GB 207.00 166.94 0.65 1.53
SSD Corsair Force GT 240GB 240 GB 225.00 181.45 0.76 1.32
SSD Corsair Neutron 128GB 128 GB 123.00 99.19 0.77 1.29
USB Flash Sandisk Cruzer Flash Drive 32GB 32 GB 31.00 25.00 0.78 1.28
SSD Corsair Force GT 120GB 120 GB 128.00 103.23 0.86 1.16
SDXC Sandisk Ultra SDXC, Class 10, 15/30MB/s, 64GB 64 GB 75.00 60.48 0.95 1.06
USB Flash Sandisk Cruzer Flash Drive 16GB 16 GB 19.00 15.32 0.96 1.04
USB Flash Sandisk Ultra Cruzer BACKUP 64GB 64 GB 77.00 62.10 0.97 1.03
SDHC Sandisk Ultra, Class 10, 15/30MB/s, 32GB 32 GB 41.00 33.06 1.03 0.97
SDXC Sandisk Extreme SDXC, UHS-I, 45MB/s, 128GB 128 GB 208.00 167.74 1.31 0.76
USB Flash Sandisk Cruzer Blade 8GB 8 GB 13.00 10.48 1.31 0.76
SDXC Sandisk Extreme SDXC, UHS-I, 80/60MB/s, 64GB 64 GB 115.00 92.74 1.45 0.69
SDHC Sandisk Ultra, Class 10, 30MB/s, 16GB 16 GB 29.00 23.39 1.46 0.68
SDHC Sandisk Ultra, Class 10, 30MB/s, 8GB 8 GB 18.00 14.52 1.81 0.55
SDXC Sandisk Extreme Pro SDXC, UHS-I, 95/45MB/s, 64GB 64 GB 148.00 119.35 1.86 0.54
SDHC Sandisk Extreme, Class 10, 30MB/s, 16GB 16 GB 38.00 30.65 1.92 0.52
SDHC Sandisk Extreme Pro, Class 10, 90/95MB/s, 32GB 32 GB 78.00 62.90 1.97 0.51
SDHC Sandisk Extreme, Class 10, 30MB/s, 8GB 8 GB 21.00 16.94 2.12 0.47
Compact Flash SanDisk Ultra 200x, 16GB 16 GB 50.00 40.32 2.52 0.40
Compact Flash SanDisk Extreme 400x, 60MB/s, 64GB 64 GB 200.00 161.29 2.52 0.40
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 8GB 8 GB 27.00 21.77 2.72 0.37
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 16GB 16 GB 55.00 44.35 2.77 0.36
Compact Flash SanDisk Extreme 400x, 60MB/s, 32GB 32 GB 112.00 90.32 2.82 0.35
Compact Flash Sandisk Extreme 800x, 120MB/s, 128GB 128 GB 457.00 368.55 2.88 0.35
Compact Flash Sandisk Extreme 800x, 120MB/s, 64GB 64 GB 230.00 185.48 2.90 0.35
Compact Flash Sandisk Extreme Pro 160MB/s, 64GB 64 GB 365.00 294.35 4.60 0.22
Compact Flash Sandisk Extreme Pro 160MB/s, 256GB 256 GB 1479.00 1192.74 4.66 0.21
Compact Flash Sandisk Extreme Pro 600x, 90MB/s, 32GB 32 GB 191.00 154.03 4.81 0.21
Compact Flash SanDisk Extreme 400x, 60MB/s, 8GB 8 GB 48.00 38.71 4.84 0.21
Compact Flash SanDisk Extreme 400x, 60MB/s, 16GB 16 GB 98.00 79.03 4.94 0.20
Compact Flash Sandisk Extreme Pro 160MB/s, 128GB 128 GB 786.00 633.87 4.95 0.20
Compact Flash Sandisk Extreme Pro 600x, 90MB/s, 16GB 16 GB 102.00 82.26 5.14 0.19

Exchange rate: 1 Euro = 1.240000 CHF.

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Storage prices

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The wobbly economy seems to have stalled the improvements in prices seen at the beginning of the year, and certain SSD and memory offerings are now slightly more expensive than in February. Spinning disks have declined a bit, but we will probably have to wait till the end of the year, when the new 5 TB disks come online, to see significant shifts.

On the bright side, 4 TB disks are now really taking off, with the Seagate Barracuda 4 TB now just marginally more expensive than the WD Green 3 TB in terms of bucks per GB. Also interesting, is the WD Red offering, which at only 10 Euros difference to the Green 3 TB counterpart now looks like a very good deal. The difference is the manufacturer warranty at 3 vs. 2/1 years, but also in number of platters, 3 for the former, while Green is still on 4 x 750 GB (as far as I know). Since my old HD is shown critical signs of ageing, I might just pick up one of those.

Finally, I’ve also updated the long term history chart at hblok.net/storage. Again, somewhat sideways movement for some of the items.

Media Type Product Capacity Price CHF Price Euros Euros / GB GBs / Euro
Harddisk Western Digital Caviar Green 3TB 3000 GB 137.00 111.38 0.04 26.93
Harddisk Seagate Barracuda 4TB 4000 GB 185.00 150.41 0.04 26.59
External 3.5 Western Digital My Book Essential Edition 3TB, USB3 3000 GB 144.00 117.07 0.04 25.63
External 3.5 Western Digital My Book Essential Edition 4TB, USB3 4000 GB 195.00 158.54 0.04 25.23
Harddisk Western Digital Red 3TB 3000 GB 149.00 121.14 0.04 24.77
Harddisk Western Digital Caviar Green 2TB 2000 GB 105.00 85.37 0.04 23.43
Harddisk Hitachi Deskstar 7K4000, 4TB 4000 GB 229.00 186.18 0.05 21.48
External 3.5 Western Digital My Book Essential Edition 2TB, USB3 2000 GB 115.00 93.50 0.05 21.39
Harddisk Western Digital Caviar Black 4TB 4000 GB 284.00 230.89 0.06 17.32
Harddisk Western Digital Caviar Green 1TB 1000 GB 72.00 58.54 0.06 17.08
External 2.5 Western Digital My Passport 2TB, USB3 2000 GB 149.00 121.14 0.06 16.51
Harddisk Western Digital RE 4TB 4000 GB 368.00 299.19 0.07 13.37
External 3.5 Western Digital My Book Essential Edition 1TB, USB3 1000 GB 105.00 85.37 0.09 11.71
Blu-ray Verbatim BD-R SL 25 @ 50GB 1250 GB 238.00 193.50 0.15 6.46
DVD+R DL Verbatim 8x DVD+R DL 25 @ 8,5GB 213 GB 42.00 34.15 0.16 6.22
DVD-R Verbatim 16x DVD-R 100 @ 4,7GB 470 GB 96.00 78.05 0.17 6.02
DVD+R DL Verbatim 8x DVD+R DL 10 @ 8,5GB 85 GB 36.00 29.27 0.34 2.90
CD-R Verbatim CD-R 100 @ 700MB 70 GB 35.00 28.46 0.41 2.46
SSD Samsung SSD 840 Basic, TLC, 500GB 500 GB 329.00 267.48 0.53 1.87
SSD Corsair Neutron 256GB 256 GB 212.00 172.36 0.67 1.49
SSD Sandisk Extreme 480GB 480 GB 400.00 325.20 0.68 1.48
USB Flash Sandisk Cruzer Flash Drive 32GB 32 GB 29.00 23.58 0.74 1.36
SSD Corsair Force GT 240GB 240 GB 224.00 182.11 0.76 1.32
SSD Corsair Neutron 128GB 128 GB 125.00 101.63 0.79 1.26
SSD OCZ Agility 3 120GB 120 GB 119.00 96.75 0.81 1.24
SSD OCZ Vertex 3 240GB 240 GB 239.00 194.31 0.81 1.24
SSD OCZ Vertex 4 128GB 128 GB 136.00 110.57 0.86 1.16
SSD Corsair Force GT 120GB 120 GB 131.00 106.50 0.89 1.13
USB Flash Sandisk Ultra Cruzer BACKUP 64GB 64 GB 70.00 56.91 0.89 1.12
USB Flash Sandisk Cruzer Flash Drive 16GB 16 GB 19.00 15.45 0.97 1.04
SDXC Sandisk Ultra SDXC, Class 10, 15/30MB/s, 64GB 64 GB 78.00 63.41 0.99 1.01
SDXC Sandisk Extreme SDXC, UHS-I, 45MB/s, 128GB 128 GB 168.00 136.59 1.07 0.94
SSD OCZ Agility 3 240GB 240 GB 322.00 261.79 1.09 0.92
SDHC Sandisk Ultra, Class 10, 15/30MB/s, 32GB 32 GB 43.00 34.96 1.09 0.92
USB Flash Sandisk Cruzer Blade 8GB 8 GB 13.00 10.57 1.32 0.76
SDXC Sandisk Extreme SDXC, UHS-I, 45MB/s, 64GB 64 GB 114.00 92.68 1.45 0.69
SDHC Sandisk Ultra, Class 10, 30MB/s, 16GB 16 GB 29.00 23.58 1.47 0.68
SDHC Sandisk Ultra, Class 10, 30MB/s, 8GB 8 GB 16.00 13.01 1.63 0.61
SDHC Sandisk Extreme, Class 10, 30MB/s, 16GB 16 GB 35.00 28.46 1.78 0.56
SDHC Sandisk Extreme, Class 10, 30MB/s, 8GB 8 GB 18.00 14.63 1.83 0.55
SDXC Sandisk Extreme Pro SDXC, UHS-I, 95/45MB/s, 64GB 64 GB 148.00 120.33 1.88 0.53
SDHC Sandisk Extreme Pro, Class 10, 90/95MB/s, 32GB 32 GB 78.00 63.41 1.98 0.50
Compact Flash SanDisk Ultra 200x, 16GB 16 GB 50.00 40.65 2.54 0.39
Compact Flash SanDisk Extreme 400x, 60MB/s, 64GB 64 GB 200.00 162.60 2.54 0.39
Compact Flash SanDisk Extreme 400x, 60MB/s, 32GB 32 GB 102.00 82.93 2.59 0.39
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 8GB 8 GB 27.00 21.95 2.74 0.36
SDHC Sandisk Extreme Pro, Class UHS-I, 90/95MB/s, 16GB 16 GB 55.00 44.72 2.79 0.36
SDHC Sandisk Extreme, Class 6, 20MB/s, 4GB 4 GB 17.00 13.82 3.46 0.29
Compact Flash Sandisk Extreme Pro 600x, 90MB/s, 64GB 64 GB 329.00 267.48 4.18 0.24
Compact Flash Sandisk Extreme Pro 100MB/s, 128GB 128 GB 659.00 535.77 4.19 0.24
Compact Flash Sandisk Extreme Pro 600x, 90MB/s, 32GB 32 GB 174.00 141.46 4.42 0.23
Compact Flash SanDisk Extreme 400x, 60MB/s, 16GB 16 GB 89.00 72.36 4.52 0.22
Compact Flash SanDisk Extreme 400x, 60MB/s, 8GB 8 GB 47.00 38.21 4.78 0.21
Compact Flash Sandisk Extreme Pro 600x, 90MB/s, 16GB 16 GB 103.00 83.74 5.23 0.19

Exchange rate: 1 Euro = 1.230000 CHF.

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Concerns about SSD reliability debunked (again)

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Update: Empirical evidence to go with the theoretical numbers.
Summary: It checks out; SSDs last a very long time.

Background

The myths about how you should use an SSD, and what you should not do with it keep on spinning. Even if there are frequent articles which crunch the actual numbers, the superstition persists. Back in 2008, Robert Penz concluded that your 64 GB SSD could be used for swap, a journalling file system, and consumer level logging, and still last between 20 and 50 years under extreme use.

Fast forward to 2013, with 120 and 240 GB drives becoming affordable, the problem should have virtually disappeared from consumer grade hardware, but people are still worried. So when Magnus Deininger did some estimates on SSD stress testing, he got flack from Slashdot since he did not cover the consumer level disks. The write endurance and number of estimated write cycles on a single block before it goes bad varies widely between consumer and enterprise grade disks, ranging from only 1000 cycles to a million. This article from Centon explains why that is. As can be seen from the simplified figure below, the cheaper consumer drives using “TLC” (Three Layer Cell) or “MLC” (Multi Layer Cell) memory cram the data a lot closer, and thus degrade quicker than enterprise grade “SLC” (Single Layer Cell) memory.

Stress test of consumer SSD

Deininger concerned himself only with the high end drives, with 100k to 1M write cycles, while most folks over at Slashdot seems to have the low end ones, at 1k – 10k write cycles, and thus the furore. However, Deininger’s estimates were also skewed against the high end drives, since he used the maximum write speed of the SATA 3 controller, which at 6 Gbit/s (750 MByte/s) is lot more than the ~500 MB/s a typical SSD is rated for, or the ~250 MB/s you probably get out of it on a consumer system. And even that is still estimates for a stress tests, and does not even start to model a typical consumer usage pattern.

Deininger goes into detail on how he came up with the estimates, and also how to plot his graphs in Gnuplot. So based on that, let’s run a few numbers, covering the 10k and 1k disks and typical use. However, let’s first drop the stress test write speed down from max controller speed to typical system speed of 250 MB/s. Also, for his plots, he uses multiples of 1024, which for flash memory based drives might be correct, but is not universally used; for example Intel specifies in GB (base 10), while OCZ in GiB (base 2). For transfer speed, this is wrong, as base 10 is the norm. Although it does not make a big difference, I’ve changed to base 10 numbers.

The graphs show time on the x-axis (days on the two first, and years in the next section), and the fraction of broken memory cells (or blocks) on the y-axis. That is, from 0 damaged cells, to 100% or all of them at the top. A horizontal lines marks the 10% point in all graphs since this is usually the point where damaged cells will be visible to the end user. Before that, the internal write levelling on the disk controller will hide these cells, since most disks come with about 10% space reserved for this. (Thus a disk with 128 GiB space is sold as 120 GB, and 256 GiB is sold as 240 GB).

First, there are a few fundamentals based on Deininger equations which can be seen in his examples, and also becomes clear in the graphs above: Doubling storage capacity of the drive doubles the time to failure (at the 10% line). And increasing flash lifespan by a factor of ten also increases time to failure by a factor of ten. All linear relationships, and no magic there, in other words.

For the three drive sizes considered (I dropped the 32 GB size, as I did not find it worthwhile for almost any application any more), the failure times at 10.000 write cycles are 26, 51, and 103 days for 64, 128 and 256 GB respectively. For TLC memory, at only 1000 cycles, the times are thus also a tenth; 2.6, 5.1 and 10.3 days.

If you were to conduct a stress test of drives from different manufactures, these numbers would be interesting. You could for example do the write, check and remove operations continuously till you start to see errors on the data written. However, as read speeds are typically around the same as write speeds for most SSDs, it would actually take at least twice as long as the points in these graphs. (The remove operation also has to be factored in, but is only a fraction of full read and write).

Typical usage

For any performance test it is important to understand where the critical failure points are. However, it does still not tell us what will happen on a typical home user system. A typical consumer would not fill up his whole drive multiple times a day, only to remove it all and start over. So how best to simulate typical user behaviour. Well, we could of course just leave the drive in a machine, and run user software over many years to see what happens. That would not be practical, as we’d never get any useful results in a reasonable time. So, we’re left with estimates, but at a different write speed than the stress test above.

How much would a typical user write to his disk? There will be different use cases of course, but let’s assume two scenarios: a low to medium use case, where 1 GB is written every day, and a heavy home user who writes 1 GB an hour, every day (although, even that is probably beyond what could be labelled as consumer usage). At this point, a table of the different speeds and units comes in handy, so we can wrap our head around the numbers. It then becomes clear how extreme the 250 MB/s stress test actually is, as it will fill up a 64 GB disk 337 times over in 24 hours (250 MB/s * (24*60*60) second = 21600 GB. And 21600 / 64 GB = 337.5 times).

MBit/s MByte/s MByte/hour GByte/day GByte/year
SATA3 max speed 6000 750 2700000 64800 23652000
Stress test 2000 250 900000 21600 7884000
Heavy use 2.2222 0.2778 1000 24 8760
Low/Medium use 0.0926 0.0116 41.67 1 365

Now for some graphs. You’ll have to watch them carefully as the plotted lines are all the same, the y-axis are all the same, the disk sizes are the same, and the only parameters changing are write speed; 1 GB vs. 24 GB a day, and cell cycle life span; 10k vs. 1k. And watch out for the x-axis which are now in years, instead of days above. The first graph shows 10k write cycle disks, where 1 GB is written every day. The smallest disk, at 64 GB, will then last for 1524 years!

Can that be right, you ask? There must be some a mistake in the numbers somewhere? Well, let’s do a quick check to see if it matches Deininger’s graphs: First, his plots were in days, so 1524 years makes 1524 * 365 = 556260 days. Next, the ratio between 6 GBit/s and 1 GByte / day we get from the table above: 64800 (GB / day). Finally, In his first graph, he considered 100k write cycle disks, so we multiply by a factor of 10. Plug in the numbers: 556260 / 64800 * 10 = 86. Exactly matching 86 days for the 64 GB disk at 100k cycles in his first graph. The math works out.

Even in the most unrealistic use case, where a 64 GB drive rated for 1000 write cycles (TLC memory) is filled up almost three times per week, it will last more than six years before the first dead memory cells are likely to show. Moving to a MLC based drive at 10k (still consumer grade), the time to failure moves to 63 years, most likely far outlasting the system it was hosted in, or maybe even the consumer who bought it.

(For the Gnuplot scripts to generate all the graphs above, please see this file).

Conclusion

So will Sold State Drives last till the end of time? Of course not! In fact, plenty of other components are prone to fail just the same way as in old HDDs: Capacitors are infamous for their short lifespan; solder joins might crack. The important point is, it is not the memory cells which are likely to fail first, even under the most extreme use.

Still, it makes sense to deploy tools fit for purpose: An enterprise drive drive using SLC memory, with 100k or 1M write cycles will leave all doubts behind. There will be no need to consider special use cases or take special precautions (beyond normal backup and security procedures which should be in place regardless of drive type). For the home user, the same is true: Even the smallest drives with shortest cell lifespan will not fail under normal use.

More specifically, there are no problems or worries with

  • using ext3, ext4 or other journalling file systems on an SSD.
  • storing /tmp or logs on the SSD.
  • using an SSD partition for memory swap.
  • any normal consumer usage pattern.

In summary: Exchanging the old spinning disk with solid state will pose no extra risk of data loss. It will of course not reduce the risk of loss from other threats either, so normal backup and security procedures should always be in place.

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Historical Cost of Computer Memory and Storage

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Computer storage, primary and secondary memory, has seen a tremendous phase of development over the last fifty years. As new technology has been brought to the market prices have continued to decline steadily at a logarithmic scale. For magnetic storage, the trend has been very stable over the last thirty years, with prices per MB going down around a third every year, or a ninety percent every five years. For primary storage, the trend has been more volatile, but overall we see a similar rate of decline all the way back to the first flip-flops in the 1950s.

John C. McCallum has done a good job collecting all the data over the years, and going back to computer magazines for reference. However, since the beginning of 2012 there have been no updates, so I’ve taken up the work where he left off. I’ve added a new page to my site, where I will collect the data and update the graphs over time: hblok.net/storage


(Click image for larger version)

In the first update, the harddisk prices are most interesting, and we can now clearly see the effect of the flood disaster in late 2011. It has interrupted a thirty year trend, and as a result prices are about the same per MB as they were one and a half years ago. Now the question is, will this have a lasting effect on the magnetic harddisk prices, or will it be just a blip in history, as technological improvements bring us cheaper storage at the same phase.

The two plots below extrapolate the trend over the last thirty years, with two different scenarios: 1) Improvements in technology will catch up with the delay over the last year, and thus the thirty year trend will continue unaffected (red line). Or 2) phase of improvments will not change, and thus the rate of decline in price will stay the same, but shift the line by about a year (blue line).


(Click image for larger version)

The price is 4 cents per GB today (4e-5 per MB). If we look two years ahead, with the uninterrupted scenario (red line), the price would be 0.5 cents per GB in 2015 (5e-6 per MB), or put in different ways: 3 TB of storage which costs $125 today would have to go down to about $15 in two years, or for the same $125 you’d have to get a whopping 25 TB (yes, twenty five!). Given the recent news from the major harddisk vendors, that seems rather unlikely to happen; they’re only planning for 5 TB drives at the end of this year. So, over two years time, prices will not catch up. Perhaps this will change looking even further ahead, however, extrapolating technological trends beyond a year or two is merely guessing.

If we look at the second scenario, where we assume that the prices will continue to decline at the same rate as they have done in the past, given today’s price we’re then looking at about 1.5 cents per GB (1.6e-5 per MB). That would mean that today’s 3 TB would go for around $50, while $125 would buy you about 8 TB. That seems more reasonable, and also in line with what products are being brought to market and in research right now. If the rumoured 5 TB Western Digital disk will be realised with four platters (4 * 1.25 TB) at the end of this year, it means five platter 6.25 TB (5 * 1.25) disks are already a possibility. Increasing storage density another 30% to reach 8 TB over the following year seems a reasonable assumption.

Edit: A previous version of this article placed the decimal point for price per GB incorrectly, at 0.4 cents rather than 4 (although the other numbers were unchanged, as were the extrapolated predictions).